xref: /dragonfly/sys/cpu/x86_64/include/endian.h (revision a3127495)
1 /*-
2  * Copyright (c) 1987, 1991 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)endian.h	7.8 (Berkeley) 4/3/91
30  * $FreeBSD: src/sys/amd64/include/endian.h,v 1.5 2003/09/22 22:37:49 peter Exp $
31  */
32 
33 #ifndef _CPU_ENDIAN_H_
34 #define	_CPU_ENDIAN_H_
35 
36 #ifndef _KERNEL
37 #include <sys/cdefs.h>
38 #endif
39 
40 #include <machine/stdint.h>
41 
42 /*
43  * Define the order of 32-bit words in 64-bit words.
44  */
45 #define	_QUAD_HIGHWORD 1
46 #define	_QUAD_LOWWORD 0
47 
48 /*
49  * Definitions for byte order, according to byte significance from low
50  * address to high.
51  */
52 #define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
53 #define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
54 #define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
55 
56 #define	_BYTE_ORDER	_LITTLE_ENDIAN
57 
58 /*
59  * Deprecated variants that don't have enough underscores to be useful in more
60  * strict namespaces.
61  */
62 #if __BSD_VISIBLE
63 #define	LITTLE_ENDIAN	_LITTLE_ENDIAN
64 #define	BIG_ENDIAN	_BIG_ENDIAN
65 #define	PDP_ENDIAN	_PDP_ENDIAN
66 #define	BYTE_ORDER	_BYTE_ORDER
67 #endif
68 
69 #ifdef __GNUC__
70 
71 #define __word_swap_int_var(x) \
72 __extension__ ({ register __uint32_t __X = (x); \
73    __asm ("rorl $16, %0" : "+r" (__X)); \
74    __X; })
75 
76 #ifdef __OPTIMIZE__
77 
78 #define	__word_swap_int_const(x) \
79 	((((x) & 0xffff0000) >> 16) | \
80 	 (((x) & 0x0000ffff) << 16))
81 #define	__word_swap_int(x) (__builtin_constant_p(x) ? \
82 	__word_swap_int_const(x) : __word_swap_int_var(x))
83 
84 #else	/* __OPTIMIZE__ */
85 
86 #define	__word_swap_int(x) __word_swap_int_var(x)
87 
88 #endif	/* __OPTIMIZE__ */
89 
90 #define __byte_swap_int_var(x) \
91 __extension__ ({ register __uint32_t __X = (x); \
92    __asm ("bswap %0" : "+r" (__X)); \
93    __X; })
94 
95 #ifdef __OPTIMIZE__
96 
97 #define	__byte_swap_int_const(x) \
98 	((((x) & 0xff000000) >> 24) | \
99 	 (((x) & 0x00ff0000) >>  8) | \
100 	 (((x) & 0x0000ff00) <<  8) | \
101 	 (((x) & 0x000000ff) << 24))
102 #define	__byte_swap_int(x) (__builtin_constant_p(x) ? \
103 	__byte_swap_int_const(x) : __byte_swap_int_var(x))
104 
105 #else	/* __OPTIMIZE__ */
106 
107 #define	__byte_swap_int(x) __byte_swap_int_var(x)
108 
109 #endif	/* __OPTIMIZE__ */
110 
111 #define __byte_swap_long_var(x) \
112 __extension__ ({ register __uint64_t __X = (x); \
113    __asm ("bswap %0" : "+r" (__X)); \
114    __X; })
115 
116 #define	__byte_swap_long_const(x) \
117 	(((x >> 56) | \
118 	 ((x >> 40) & 0xff00) | \
119 	 ((x >> 24) & 0xff0000) | \
120 	 ((x >> 8) & 0xff000000) | \
121 	 ((x << 8) & ((__uint64_t)0xff << 32)) | \
122 	 ((x << 24) & ((__uint64_t)0xff << 40)) | \
123 	 ((x << 40) & ((__uint64_t)0xff << 48)) | \
124 	 ((x << 56))))
125 
126 #ifdef __i386__
127 
128 #define	__byte_swap_long(x)	__byte_swap_long_const(x)
129 
130 #else
131 
132 #ifdef __OPTIMIZE__
133 #define	__byte_swap_long(x)	(__builtin_constant_p(x) ? \
134 	__byte_swap_long_const(x) : __byte_swap_long_var(x))
135 #else	/* __OPTIMIZE__ */
136 #define	__byte_swap_long(x)	__byte_swap_long_var(x)
137 #endif	/* __OPTIMIZE__ */
138 
139 #endif	/* __i386__ */
140 
141 #define __byte_swap_word_var(x) \
142 __extension__ ({ register __uint16_t __X = (x); \
143    __asm ("xchgb %h0, %b0" : "+Q" (__X)); \
144    __X; })
145 
146 #ifdef __OPTIMIZE__
147 
148 #define	__byte_swap_word_const(x) \
149 	((((x) & 0xff00) >> 8) | \
150 	 (((x) & 0x00ff) << 8))
151 
152 #define	__byte_swap_word(x) (__builtin_constant_p(x) ? \
153 	__byte_swap_word_const(x) : __byte_swap_word_var(x))
154 
155 #else	/* __OPTIMIZE__ */
156 
157 #define	__byte_swap_word(x) __byte_swap_word_var(x)
158 
159 #endif	/* __OPTIMIZE__ */
160 
161 static __inline __always_inline __uint64_t
162 __bswap64(__uint64_t _x)
163 {
164 
165 	return (__byte_swap_long(_x));
166 }
167 
168 static __inline __always_inline __uint32_t
169 __bswap32(__uint32_t _x)
170 {
171 
172 	return (__byte_swap_int(_x));
173 }
174 
175 static __inline __always_inline __uint16_t
176 __bswap16(__uint16_t _x)
177 {
178 
179 	return (__byte_swap_word(_x));
180 }
181 
182 #define	__htonl(x)	__bswap32(x)
183 #define	__htons(x)	__bswap16(x)
184 #define	__ntohl(x)	__bswap32(x)
185 #define	__ntohs(x)	__bswap16(x)
186 
187 #else /* !__GNUC__ */
188 
189 /*
190  * No optimizations are available for this compiler.  Fall back to
191  * non-optimized functions by defining the constant usually used to prevent
192  * redefinition.
193  */
194 #define	_BYTEORDER_FUNC_DEFINED
195 
196 #endif /* __GNUC__ */
197 
198 #endif /* !_CPU_ENDIAN_H_ */
199